The present invention pertains to pharmaceutical injection devices, and, in particular, to a system for covering a needle of an injection device.
Patients suffering from a number of different diseases frequently must inject themselves with pharmaceuticals. A variety of devices are available to facilitate these injections, such as simple prefilled needled syringes used alone, or automatic injection devices that when triggered by a user automatically insert into the user a needle of a prefilled syringe that prior to triggering was disposed within the automatic injection device housing, and then automatically inject a dose of medication through that inserted needle.
To maintain the sterility of the needle of a syringe prior to its use, a variety of needle covers have been proposed. One type of needle cover needs to be removed by a user prior to syringe use. Such a needle cover often has a multipart construction including an inner cover and an outer cover. The inner cover is relatively flexible or elastomeric and provides a sterile barrier around the needle and forms a seal with, for example, the syringe hub from which the needle extends. The inner cover also may seal the tip of the needle such as in designs where the needle is already in fluid communication with the syringe contents. The outer cover is made of a relatively rigid material and protectively surrounds and engages the inner cover. A pulling of the outer cover from the syringe pulls off the inner cover to expose the needle for use. Another example of this type of needle cover is provided as a flexible cover without a rigid cover thereover. While such needle covers are useful, it needs to be removed from the syringe by the user prior to injection which makes it undesirable in some situations.
Another type of needle cover advantageously does not need to be removed by the user from the syringe prior to use. One example of this type of needle cover is known from WO 2013/032779. This type of needle cover is formed of a resilient material and includes a body that is collapsible. When the cover body collapses when pressed against an injection site either directly or indirectly with an apertured portion of the device in which it is used interposed, the tip of the needle within the cover pierces the cover for insertion into the user.
While a needle cover that does not have to be removed by a user is very convenient for a user of the device in which it is disposed, such design is not without potential shortcomings. For one thing, a collapsible needle cover for a needled syringe may complicate manufacture. Not only must a flexible needle cover be assembled over the needle, but when so assembled the needle still needs to be protected from damage, and people protected from accidental needle sticks, as the needle cover is handled throughout any remaining processes of manufacture. Still further, unless the needle cover is securely attached around the needle there is a possibility that after such attachment, be it during further manufacture, distribution or use preparation, the needle cover could come off from or lose its needle sterility-maintaining seal with the rest of the device.
Thus, it would be desirable to provide a needle covering system that can overcome one or more of these and other shortcomings of the prior art.